EA015596B1 - Branched ionomers and a process for preparing thereof - Google Patents

Abstract

A branched aromatic ionomer is prepared by co-polymerizing a first monomer having an aromatic moiety and an unsaturated alkyl moiety and a second monomer having an ionic moiety and at least one unsaturated moiety. The ionic moiety may have a cationic group having a valence of +1 or greater. Styrene is among the useful first monomers and sodium methacrylate and zinc dimethacrylate are among the useful second monomers. The branched aromatic ionomers may be used to prepare articles including foamed polystyrene and microwave save dishes and utensils.

Description

The present invention relates to polymers, in particular ionomers.

When creating polymers it may be desirable to add a branch to the polymer chains or to increase it. Increased branching can cause changes in the physical properties of the polymer, including increased strength, stability at higher temperatures, and increased hardness. In some cases, increased branching may improve properties such as elastomeric behavior and abrasion resistance.

As you know, ionomers are used in many areas of technology. For example, a polyester-based ionomer that improves dyeability can be obtained from the reaction residue of an aryl carboxylic acid sulfonate salt, an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, an aliphatic diol, or any ester capable of forming them. A photo-curable dental cement can be made using a photo-curable ionomer, which is defined as a polymer having a sufficient amount of lateral ionic groups to carry out a precipitation reaction in the presence of a reactive filler and water and a sufficient amount of side polymerization groups, to ensure the polymerization of the resulting mixture, for example, by curing when exposed to energy radiation.

Another use for ionomers is in the field of manufacturing abrasive surfaces. Suitable ionomers for this application are copolymers of ethylene with salts of unsaturated acids, such as the zinc salt of acrylic acid. Typical commercial products of this type include Ac1up®, Sshnap ™, Soa1ylepepe®, Sig1up®, and Exog® polymers. Sig1up®, of course, is a well-known component of covering some high-quality golf balls.

On the one hand, the present invention is a branched aromatic ionomer obtained by copolymerizing a first monomer having an aromatic moiety and an unsaturated alkyl moiety, and a second monomer having an ionic moiety and at least two unsaturated moieties. In this case, the ion fragment has at least two ionizable groups: a cationic group that ionizes to form cations, and an anionic group that ionizes to form anions, while the cationic group is multivalent and can form bridges with other molecules in the presence of ions of the appropriate type and in suitable concentration.

On the other hand, the present invention is a branched aromatic ionomer obtained by copolymerizing a first monomer having an aromatic moiety and an unsaturated alkyl moiety, and a second monomer having an ionic moiety and at least one unsaturated moiety. In this case, the ion fragment has at least two ionizable groups: a cationic group that ionizes to form cations, and an anionic group that ionizes to form anions, with the cationic group being monovalent.

Another aspect of the present invention is a method for producing branched aromatic ionomers. The method includes the copolymerization of a first monomer having an aromatic fragment and an unsaturated alkyl fragment, and a second monomer having an ion fragment and at least one unsaturated fragment.

In yet another aspect, this invention is a manufactured product. The product is formed from a branched aromatic ionomer made by copolymerizing a first monomer having an aromatic moiety and an unsaturated alkyl moiety, and a second monomer having an ionic moiety and at least one unsaturated moiety. In this case, the ion fragment has at least two ionizable groups: a cationic group that ionizes to form cations, and an anionic group that ionizes to form anions, with the cationic group being monovalent.

Brief Description of the Drawings

For a detailed understanding and adequate assessment of the present invention, reference should be made to the following detailed description of the invention and preferred embodiments thereof, which should be read in conjunction with the accompanying description drawings, where FIG. 1 is a graph of the degree of conversion from time to time when carrying out the reactions described in Example 2;

FIG. 2 is a graph showing the results of molecular weight measurements during the reactions described in Example 2;

FIG. 3 is a graph showing the results of measuring the melt flow rate during the reactions described in Example 2;

FIG. 4 is a graph showing the results of measuring the glass transition temperature during the reactions described in Example 2;

FIG. 5 is a graph of the degree of conversion from time to time when carrying out the reactions described in Example 3;

FIG. 6 is a graph showing the results of molecular weight measurements during the reactions described in Example 3;

FIG. 7 is a graph showing the results of measuring the glass transition temperature during the reactions described in Example 3;

- 1 015596 of FIG. 8 is a graph showing the results of measurement of melt flow during the reactions described in Example 3.

It is understood that the drawings do not need to be scaled and that the proportions of the individual parts in the drawings can be increased to display details.

In the field of polymers, the term ionomer is defined as a polymer with covalent bonds between elements of the polymer chain and ionic bonds between individual polymer chains. Ionomers are also defined as polymers containing ionic bonds between chains. Thermoplastic ionomers have the unique property of forming reversible crosslinks. During processing at melting points, these crosslinks are separated, and when the material is cooled to the glass transition temperature, they are restored.

Branched aromatic ionomers can be formed by copolymerizing a first monomer having an aromatic moiety and an unsaturated alkyl moiety, and a second monomer having an ionic moiety and at least one unsaturated moiety. For example, suitable monomers having an aromatic moiety and an unsaturated alkyl moiety may include monovinyl aromatic compounds, such as styrene, as well as alkylated styrenes, where the alkyl radical is attached to the benzene ring or to the side chain. Alpha-methylstyrene, t-butylstyrene, p-methylstyrene and vinyltoluene are suitable monomers that can be useful for the preparation of branched aromatic ionomers. Monovinyl aromatic compounds can be used individually or as mixtures. In one of the embodiments of the invention, styrene is exclusively used as the first monomer. Any monomer having an aromatic moiety and an unsaturated alkyl moiety can be used to prepare branched aromatic ionomers.

The second monomer has an ionic moiety, a moiety and at least one unsaturated moiety. The ionic fragment has at least two groups capable of ionization, one of which ionizes to form cations, and the other to form anions. In one embodiment of the invention, the group ionizing with the formation of cations, hereinafter cationic group, is monovalent. In another embodiment of the invention, the cationic group is multivalent and is capable of forming bridges with other molecules in the presence of ions of the appropriate type and concentration.

When a cationic group is monovalent, it is a monovalent metal or a compound that forms a quaternary ammonium ion. Suitable metals include sodium, potassium, cesium, silver and the like. Suitable quaternary ammonium compounds include ammonium chloride, methyl ammonium chloride, diethylammonium chloride, and the like.

When a cationic group is a group capable of forming bridges with other molecules in the presence of ions of a suitable type and concentration, then it is a group that ionizes to form cations with a charge of +2 or higher. In one design, the cationic group may be a metal having an oxidation state of +2 or higher. Suitable metals include zinc, copper, lead, calcium, magnesium, zirconium, aluminum and the like.

The second ionizing group is an organic group that ionizes to form an anion with a coordination charge of -1 or lower. Suitable groups include anions of amines, carboxylic acids, sulfonic acids, phosphonic acids, thioglycolic acids and the like. If the valence of the cationic group is higher than +1, then the first and second ionizing groups can form a bridge.

The anionic group includes at least one polymerizable unsaturated moiety. In some embodiments, this fragment is unique. In other embodiments of the invention, these fragments may be two or more. The unsaturated portion may be represented by a carbon-carbon terminal or non-terminal double bond.

Compounds suitable as a second monomer can be obtained from a metal cation and an organic anion having at least one unsaturated bond. Suitable compounds that can be used as a second monomer include any compounds of the general formula [k —A ² - ^ y-M ^x where B is a hydrocarbon chain containing from 2 to 40 carbon atoms and at least one polymerizable unsaturated bond;

A is an anionic group;

M is a cationic group;

Ζ is -1 or -2;

X is +1, +2, +3, +4 or +5;

y is an integer having a value from 1 to 4.

When y is 1, B may have one or more polymerized unsaturated bonds. In those embodiments of the invention, where y is 1, B may have two or more polymerized unsaturated bonds, and these bonds may be located on separate chains or rather far from each other.

- 201515596 other on the same chain, so that polymerization is possible without significant steric difficulties. In some embodiments of the invention, (y-2) + X = 0, and this means that only those anionic groups that have polymerized unsaturated bonds will be coordinated with group M, however, the claims include those cases where additional groups that do not have polymerized unsaturated bonds can be coordinated with group M. When this happens, there can still be at least two polymerized unsaturated bonds coordinated with group M in addition to any other coordinated groups.

Compounds that can be used as the second monomer of the present invention include (but are not limited to) zinc diacrylate, zinc dimethyl acrylate, zinc divinyl acetate, zinc diethyl fumarate, etc .; copper diacrylate, copper dimethyl acrylate, copper divinyl acetate, copper diethyl fumarate, etc .; aluminum triacrylate, aluminum trimethyl acrylate, aluminum trivinylacetate, aluminum triethyl fumarate, etc .; zirconium tetraacrylate, zirconium tetramethyl acrylate, zirconium tetravinylacetate, zirconium tetraethyl fumarate, etc. In the case of compounds having monovalent cationic groups, the second monomer can be sodium acrylate, sodium methacrylate, silver methacrylate, etc. These compounds, as well as any compound suitable as a second monomer, can be obtained, for example, by reacting an organic acid or anhydride with a metal or metal salt. When the cationic group is polyvalent, it is possible to conduct the reaction of the organic acid with the polyvalent metal in such conditions that provide a bridge between the anionic group and the cationic group. Compounds suitable as second monomer can be obtained by any method known to those of ordinary skill in the art of synthesizing suitable monomers.

The monomers used to produce branched aromatic ionomers can interact in several ways that affect the physical properties of the ionomers. The first method consists in the formation of covalent bonds due to the polymerization of unsaturated fragments.

The second way of possible interaction of monomers used to obtain branched aromatic ionomers is to form a bridge in which a multivalent cationic group is coordinated with two anionic groups that are connected to carbon skeletons of at least two separate chains. Such coordination can actually crosslink two chains and thereby increase the total effective molecular weight of the segment to the sum of the molecular weights of the two chains.

The third way of possible interaction of monomers used to obtain branched aromatic ionomers is to form multiple bridges, as described in the previous paragraph. The more crosslinking occurs, the less elastic the three-dimensional structure of the ionomer becomes, which can lead to lower melt flow values and an increase in melt strength.

In another, fourth, way of interaction, cationic groups are monovalent, ionic fragments that are not fully involved in the formation of bridge bonds can still be associated due to hydrophobic-hydrophilic forces. In these embodiments of the invention, these weaker, but still measurable forces can arise between relatively non-polar hydrophobic non-ionic parts of the molecule, which are mutually attracted, and are repelled from polar hydrophilic ionic parts of the ionomer. These forces become more noticeable as the proportion of the second monomer increases in concentration. The four ways listed are not all possible monomer interactions. Furthermore, most of the properties associated with their ionomers primary, secondary and even tertiary structure, such structure can affect the glass transition temperature (T _c) ionomers.

Both the amount of the second monomer and the type of its interaction with the first monomer determine the amount of the second monomer used. Therefore, in some embodiments of the invention, when the interaction is weak, for example when the cationic group of the second monomer is monovalent, and it is desirable to obtain a noticeable effect from the second monomer, then branched ionomers are obtained using the second monomer in a relatively large amount, typically with respect to the first monomer to the second from about 999: 1 to about 40:60. In other similar embodiments of the invention, the ratio is from about 95: 5 to about 50:50. There are such embodiments of the invention, where this ratio is from about 90:10 to about 60:40. In other embodiments, the ratio is from 80:20 to 70:30. When the interaction is very strong, for example, when the cationic group is two or trivalent, or when it is desirable to obtain only a small change in the properties of the ionomer by introducing a second monomer, the amount of the second monomer is quite small: in the range from about 10 ppm to about 10,000 ppm . In other such ionomers, the range is from about 100 to about 1000 ppm. There are cases when in other similar ionomers this range is from about 250 to about 800 ppm.

The branched aromatic ionomer is obtained by copolymerizing the first and second monomers.

- 3 015596

Each of these monomers has at least one polymerizable unsaturated bond. The polymerization can be carried out by any method known to those of ordinary skill in the art of polymerization reactions. For example, the polymerization can be carried out using a polymerization initiator.

Examples of polymerization initiators include, in particular, radical polymerization initiators, such as benzoyl peroxide, lauroyl peroxide, tert-butylperoxybenzoate and 1,1-di-tert-butylperoxy-2,4-di-tert-butylcyclohexane. The amount of polymerization initiator is from about 0 to about 1% by weight of the monomers. In one of the embodiments of the invention, the amount of polymerization initiator is from about 0.01 to about 0.5% by weight of the monomers. In another embodiment of the invention, the amount of polymerization initiator is from about 0.025 to about 0.05% by weight of the monomers.

Alternatively, the ionomer can be obtained by using heating rather than a substance as an initiator. The ionomer can be obtained using an unconventional initiator, such as the metallocene catalyst described in US Pat. No. 6,706,827, which is incorporated herein in its entirety by reference. In one of the embodiments of the invention, the monomers can be mixed with a solvent and then subjected to polymerization. In another embodiment of the invention, one monomer is dissolved in the other and then polymerized. In yet another embodiment of the invention, the monomers can be fed separately in parallel streams to the reactor either in pure form or dissolved in a solvent such as mineral oil. And in yet another embodiment of the invention, the second monomer can be obtained ίη si or directly before polymerization, by admixing the starting components, such as unsaturated acid or anhydride and metal alcoholate, at the feed line or in the reactor. For the polymerization of monomers having polymerizable unsaturated bonds, any method known to those of ordinary skill in the art can be used. For example, you can use the method described in US Pat. No. 5,540,813, and it is entirely incorporated into this description by reference. The methods described in US Pat. Nos. 3,660,535 and 3,658,946 can also be used, and both of them are entirely included in this specification. Any method of producing general purpose polystyrene can be used to synthesize branched aromatic ionomeric polymers.

In certain embodiments of the invention, the ionomers can be mixed with additives before using them for the final application. For example, ionomers can be mixed with fire retardants, antioxidants, lubricants, pore formers, UV stabilizers, antistatic agents, and the like. Any additive that is known to ordinary experts in the field of ionomer synthesis is useful can also be used in the synthesis of branched ionomers.

Ionomers can be used in the same way as general purpose polystyrene, but they can also be used for other applications. They can be foamed to obtain polystyrene foam. Ionomers can be used in applications that require resistance to high temperatures, for example, for the manufacture of dishes and utensils for microwave ovens. Ionomers can be used to make other products, such as containers, as well as parts for cars, toys, etc. Polar ionic ionomer fragments can increase their compatibility with polyesters such as polyethylene terephthalate and polycarbonate, so that branched ionomers can be used in mixtures and alloys with these and other polymers of similar polarity.

Examples

To illustrate this invention, examples are given below. These examples are not intended to limit the scope of the present invention and should not be interpreted as such. Quantities are given in mass fractions or mass percent, unless otherwise specified.

Example 1

Polystyrene homopolymer is prepared using a 500 ml reaction vessel equipped with a stirrer. Polymerization is initiated with the help of a catalyst LIREK.GOЬ233 at a concentration of approximately 170 ppm. The reaction is carried out at approximately 131 ° C (267 ° E). The initial melt flow rate of polystyrene is 3.7 dg / min. Zinc dimethacrylate (ΖηΜΑ) is added stepwise: растворηΜΑ is first dissolved in styrene, and then the solution is fed into the reactor. The reactor is allowed to stabilize and samples are taken at those points where the concentration of ΖηΜΑ in styrene is 400, 600 and 800 ppm. Samples tested, the test results are shown below in table. one.

Example 2

Essentially, this example is identical to example 1, except that the reaction is carried out at 135 ° C (275 ° E), with a catalyst concentration of LIRP.8OE®233 175 ppm. N-dodecyl mercaptan (NDM) serves as a chain transfer agent.

Example 3

Polystyrene is obtained at a constant concentration of methacrylic acid using the same procedure and equipment as in example 2, except that the acid in the feed

- 4 015596 of the solution is neutralized using bases of various valences: sodium ethoxide, calcium carbonate, aluminum isopropyl (III) and zirconium isobutylate (IV); The catalyst LIREK.8OB®233 is used at a concentration of 200 ppm. Samples tested, the test results are presented below in table. 2

Table 1

Example 1-A Example 1-B Example 1-С [ΖηΜΑ] rrt 400 600 800 Melt Index no data 3.84 3.51 Bending strength * ' no data 13808 / 95.2 13377 / 92.2 Tensile yield strength ³ no data 7421 / 51.2 7409 / 51,1 Tensile Strength ³ no data 7326 / 50.5 7290 / 50,5 Elongation ³ no data 3.0 2.5 Softening temperature according to Vika ⁴ no data 220/104 220/104 Mp ^a 94 95 94 Μνν ⁵ 249 298 315 mr 424 1978 2,433 Polydispersity ⁱⁿ 2.6 3.2 3.3

1. Standard Ά8ΤΜ (American Society for Testing Materials) 1) –1238 g / 10 min, 200 ° C / 5 kg, 10/2001.

2. Standard Ά8ΤΜ 1) -790 pounds per square inch / MPa, 1/2001.

3. Standard Ά8ΤΜ 1) -638 pounds per square inch / MPa, pounds per square inch,%, 9/2001.

4. Standard Α8ΤΜ Э-1525, ° Р / ° С, 5/2000.

5. Standard Α8ΤΜ 1) -6474.

6. Μζ / Μη.

table 2

Comparative 3 ’ 3-A 3-B 3-C H-ϋ Methacrylic acid, ppm - 1269 1269 1269 1269 Sodium, ppm ¹ - 339 - - Calcium, ppm ⁴ - - 295 - - Aluminum, ppm ³ - - - 132 - Zirconium, ppm ⁴ - - - - 336 Melt Index ⁶ 2.90 2.89 2.70 1.80 0.51 T ⁶ * with " 107.5 108.0 108.6 109.3 109.7 Mp ⁷ 124563 119328 126800 129454 114417 ΜιλΛ 256581 262625 285875 608260 1044123 Mr 391336 400917 613472 6737117 10494556 Polydispersity ⁰ 2.1 2.2 2.3 4.7 9.1

1. In the form of sodium ethoxide.

2. In the form of calcium carbonate.

3. Aluminum isopropyl (III).

4. Zirconium butylate (IV).

1. Standard Α8ΤΜ Э-1238 g / 10 min, 200 С ° / 5 kg, 10/2001.

2. Standard Α8ΤΜ Å-3418, С, inflection point (average) on the DSC curve, 7/1999.

3. Standard Α8ΤΜ Ώ-6474.

4. Μζ / Μη.

* - Not an example of the invention.

- 5 015596

FIG. 1-4 represent a graphic representation of the results obtained according to example.

2. As these drawings show, zinc dimethacrylate is an effective difunctional monomer that stimulates chain branching and increases the ζ-average molecular weight of polystyrene. Even such a low amount of 200 ppm increases the ζ-average molecular weight of polystyrene to a value close to 1,000,000 g / mol. Despite the effectiveness of this monomer as a crosslinking agent, the resulting polymers show no signs of gelation with such amounts of added monomer that give molecular weights up to 6,000,000 g / mol.

FIG. 4-8 are a graphical representation of the results obtained in example 3. They show that it is possible to synthesize various methacrylic acid salts η δίΐιι. directly in the supplied reaction mixture, even before the polymerization. They also show that when a monovalent counterion is replaced by a three- or tetravalent counterion, an increase in the weighted average molecular weight by two or three times, as well as an increase in the ζ-average molecular weight by up to 20, is observed. It is also observed that when going to a higher valence state, an increase in molecular weight is accompanied by a decrease in melt flow, however, even with a molecular weight of 1,000,000 g / mol, the material still has flow.

Claims (15)

CLAIM 1. A branched aromatic ionomer, which is a copolymerization product of a first monomer comprising an aromatic moiety and an unsaturated alkyl moiety, and a second monomer comprising an ionic moiety and at least two unsaturated moieties, wherein the ionic moiety has at least two ionizable groups: a multivalent cationic group ionized to form cations and an anionic group ionized to form anions, wherein the second monomer is selected from the group consisting of zinc diacrylate, d methylacrylate zinc divinilatsetata zinc, zinc diethyl fumarate; copper diacrylate, copper dimethyl acrylate, copper divinyl acetate, copper diethyl fumarate; aluminum triacrylate, aluminum trimethyl acrylate, aluminum trivinyl acetate, aluminum triethyl fumarate; zirconium tetraacrylate, zirconium tetramethylacrylate, zirconium tetravinyl acetate, zirconium tetraethyl fumarate and mixtures thereof, the amount of the second monomer being from 100 to 1000 ppm. 2. The ionomer according to claim 1, in which the first monomer is selected from the group consisting of styrene, alpha-methylstrol, tert-butylstyrene, p-methylstyrene, vinyltoluene and mixtures thereof. 3. The ionomer according to claim 2, in which the first monomer is styrene. 4. The ionomer according to claim 1, in which the amount of the second monomer is from 250 to 800 ppm. 5. A branched aromatic ionomer, which is the copolymerization product of a first monomer comprising an aromatic fragment and an unsaturated alkyl fragment, and a second monomer comprising an ionic fragment and at least one unsaturated fragment, wherein the ionic fragment has at least two ionizable groups: a cationic group, ionized to form cations, and an anionic group ionized to form anions, where the cationic group is a monovalent group, while the second monomer is selected from oppa, consisting of sodium acrylate, sodium methacrylate and mixtures thereof, while the amount of the second monomer is from 100 to 1000 ppm. 6. The ionomer according to claim 5, in which the amount of the second monomer is from 250 to 800 ppm. 7. The ionomer according to claim 5, in which the first monomer is selected from the group consisting of styrene, alpha-methylstrol, tert-butylstyrene, p-methylstyrene, vinyltoluene and mixtures thereof. 8. The ionomer according to claim 7, in which the first monomer is styrene. 9. A method for producing the branched aromatic ionomers according to any one of the preceding claims, comprising copolymerizing a first monomer including an aromatic fragment and an unsaturated alkyl fragment and a second monomer including an ionic fragment and at least one unsaturated fragment. 10. The method according to claim 9, in which the monomers are mixed before copolymerization or during copolymerization. 11. The method according to claim 9, in which the second monomer receive ίη si in the first monomer. 12. The method according to claim 11, in which the second monomer is obtained by mixing ίη si zinc alcoholate with methacrylic acid. 13. The method of claim 12, wherein the zinc alcoholate is zinc butylate. 14. A microwave-safe container made of an ionomer according to any one of paragraphs 18. 15. Microwave safe utensils made from an ionomer according to any one of claims 1 to 8.